Dimensional isotropy of 6H and 3C SiC under neutron irradiation

作者：Snead Lance L^*; Katoh Yutai; Koyanagi Takaaki; Terrani Kurt; Specht Eliot D

来源：Journal of Nuclear Materials, 2016, 471: 92-96.

DOI：10.1016/j.jnucmat.2016.01.010

This investigation experimentally determines the as-irradiated crystal axes dimensional change of the common polytypes of SiC considered for nuclear application. Single crystal alpha-SiC (6H), beta-SiC (3C), CVD beta-SiC, and single crystal Si have been neutron irradiated near 60 degrees C from 2 x 10(23) to 2 x 10(26) n/m(2) (E > 0.1 MeV), or about 0.02-20 dpa, in order to study the effect of irradiation on bulk swelling and strain along independent crystalline axes. Single crystal, powder diffractometry and density measurement have been carried out. For all neutron doses where the samples remained crystalline all SiC materials demonstrated equivalent swelling behavior. Moreover the 6H-SiC expanded isotropically. The magnitude of the swelling followed a similar to 0.77 power law against dose consistent with a microstructure evolution driven by single interstitial (carbon) mobility. Extraordinarily large similar to 7.8% volume expansion in SiC was observed prior to amorphization. Above similar to 0.9 similar to 10(25) n/m(2) (E > 0.1 MeV) all SiC materials became amorphous with an identical swelling: a 11.7% volume expansion, lowering the density to 2.84 g/cm(3). The as-amorphized density was the same at the 2 x 10(25) and 2 x 10(26) n/m(2) (E > 0.1 MeV) dose levels.

• 出版日期2016-4-1